Signaling



July 28, 1925. 1,547,226

w. H. MARTIN S IGNALING Filed Match so.` i920 MH jkl/ffii@ Patented 'July Qd, 1925e unirse. sra'resl y 1,547,226 Pari-:Nr orifice.

marais s; inserm, or New You, N. Y., Anacieron. ro marcan marilena im rnnnenarn COMPANY, a CORPORATION or New Yoan.

SIGNALING.

I Application Med Iarch 30', 1920. Serial No. 868,882.

.To @Zt/whom t my; comm:

Be it known that I, WILLIAM H., MARTIN, residing at New. York, in the county of Bronx and State of New York, have in-.k

vented certain Improvements in Signaling,

of which the following is a specification.

This invention rotates to signaling and is described herein with particular reference to methods of and means for transmitting and receiving ringing si nals in telephone transmission systems, alt iough itsl application isy 'd available as an additinahtelegraph or other not limited to such s stems.

In l present day te epli'one and telegraph` practice, it is customary 'to provideka-transmission system with a plurality' oflchannels each. of which serves to transmit current independently' of the others. Iuterferencevbetween the various channelsA is prevented by employing for each, different frequencies ory haiids of frequencies andapparatus selectively responsive thereto., The frequency `range is thus divided into 'a number ,of levels and a separate transmission channel is pro-y 1 vided for each frequency level. Two of the channels used in telephone practice are the Avoice channei and ther-inging-channel, the` i frequency level of the latter being generally below that off the former. In present usualI practice, for example, the ringin currents have ia frequency of 135 cycles, w `creas the. components` of 'the voice current have yfre-- quencies varying from about 300 to 2000 cycles@ V .arrangemcntnecasitates at repeater and similar' installations the provision of To prevent false operation of the signal-f t apparatus by the voice currents, I prop to employ s plurality of signaling currents differing in uency and to so arrange the signal apparatus that the same respon s only when the `said currents are appliedl to` `the line in, certain predetermined sequence.7 Interference withthe voice channel appart tusby the ringing `currents need not lbe termina comi Tnection to apply current from the, generators separate repeating or relaying apparatus for fto the line.

'tion of the arrow the operator ma ycause the signaling channel, th'us enhancing the commercial eliciency of thel transmission system.

.A good understanding ofthe invention may now be had by reference to the following description, having reference to the ac- A companying drawing, showing inf diagrammatic view a specific form and arrangement of circuits embodying the invention.

l `In this drawing reference character L desi ates a -transmission line associated Ywith which at its left end is shown a signal,

transmitting device, and at .its right end, a signal receiving device. The transmitting device comprises a switch S having a contact arm5 adapted to co-o rate with contact se ents 1, 2, 3 and 4, insulated from each en't fre uencies of current designated f1f2 and fs, ave one terminal connected to Isegments 1 2 and 3, respectively, and the other to the lcontact arm 5, a transformer 6 being interposed in this con-4 y turning arm 5 in the direcconsecutive flow of .currents of uencies f1, f3 and f, from the transmitting to the receiving station.

The signal receiving device comprises an amplifier A1hemin shown as consistin of a plurality of electron tubes. vRelays R2 and R, are associated with the output circuit of theuamplifier and rendered selectively responsive to frequencies f1, f, and A, respectively, by means of resonant circuits. comprising inductances L1, L12, L, and condensers C1, C, and 0 `respectively, R1, R, and

Ra givern the normally open circuit. of a relay which in turn verns the circuit .of a si al device herein own as an annunciator y To signal from. the transmitting to the receiving station, theoperator turns contact erinA 5 in ,the direciion eiche arrow, As this erin bridges conteo@` segment i, con rent of liii'equrnuy f1 rions over iine L into he lnmpiier A, whereby it is eugmeneefi end caused to operneetiie reiey R1. This reiey opens er conteo@ e circuit oi? rire reiey R4 end cioses ,er cominci; o the energie ing circuifi oi? i'ie reiey R2 inns preyeniing en energizefbion of reieyn.ALAI end rendering reiny R2 res onsi're *zo current of liii-eeinency 2 when suc. curreni; is eppiied 'to iine ,eiore the confteci, erin e ofi, soir/cir S ieeyes `segment l, it bridges eegruen'i 52;, so enel', cnrren; ci frequency f2 eniers che une in end ceuses the energizetion ci? reiuy R2. 'iiiis reiey cioses 'contece ai, which is in shun@ io the conect o, oi R1, so "Ps2 mnbinues to.l

be responsive 'io tire curr-ent oifirequency f2', rege-rdlessjof the deenereifzecicn of reey R1, which taires pince "W en content errn 5 leeres contact segmenc i, Reey .R2 opens et connect c the circuit o reiey El and 'thus `prei/'ems en energieetion thereof closes at coniect e che energizing cli-onu; of the relay RB, fahne rendering this reiey responsive to current of frequency fs, which current enters line L es the coneci'c erro 5 begins fro bridge segment 3 Reey Rx, is thus caused to operare ies confie@ 93 'Whereby it is rendered uneieeied by the deenergizationof relay R2, which takes piece es arm 5 `ieev'e's segmenc G. Relay R coses'contact is. end completes rinus `the circuit of re iny R4, which circuit is now uninierrupted et contacts end c because relays R1 end R2 ere deenergized. Reiuy R4 remeins energized as long es the loperetor leaves the contact erm 5 on segment 3. H che 'contact erm is rote'i'ed continuously, the signe! may be caused to eppeer iniermittenziy, aswiil be readily understood,

' It will be observed from che nboyetiiei e response o? che signeiing. .device is secured only i'f currents oreqnencies f1, f2 endif, ere Y'eppiieoi '63o the line in proper `megniinde' enel sequence. No response of the signel will be reuiizeoi ii faire currents ere on the iine simuiieneousiy "oeceuse eine circni of reiey R4 is einen heid open et contacts eend c of ,Elend REQ Neither Wii eine signei be caused (no respond if eine currents do no6; overiup, ora' er, Reese, foiiow each einer Wih iniervening iirne` inierynis of less duration einen "the reieese periods of reieys R1 end R2. ifi', will iiiemfore ice eppreeiuieci tiene 'eine iiireiihcoci einer @the sig-nei; u'iii respondio currenis on. eine? iine from sources other einen eine eignei erensuiitriny e perenne vis extrexneiy oyen thong" t e frequencies inereor` comprise obese or G1, G2 and G3. Airiiougii no voice cinennei eppereeus hes been shown in *che present rirewing, this omission uns been mede oniy to eroici unnecessary confusion, ii, beine under siood voice curren'ie ere censec eoiow mennen over the iine by telephone inerurnenhs essociated Wien ehe -terrnineis or? iii-e iine in 'the usuel mennen. v l

The errengement of the oresen'l invention,

.eher-crore, vreneiersit prsc'iiceioie tofsignei ieys Winch ere merginei io the erreur they do not respond io currenis oi? the usuel rnegniiude oi: voice currents and by seiecing theirequency f1 to have n velue of which current or reieively ierge megnieue is nur, seidoin impressed on ehe circuit by cnefvoice currenf's. Y

Although the eiooye description hns renierence( to n specic forni of emboirneni or 'die inventionak it is to be undersioo that the invention is not rims' limited in use., bui ,broadly applicable wherever che energy of one channe is robe differentiated imm extreneous energy of about, the seme frequency, in radio es Welly as in Wireirensmission systems.

What is claimed is:

L n o telephone signeling system, .e transmission line, means for impressie `i'hereon e plurality or sifnei currents of cii ferent frequencies in tie voice renge and in e preassigned sequence, selectively onernted signal 'receiving apparatus essociied with seid line', `sein signe?. eppereius iieiing nonresponsive to voice 'currents end responsive to the signni currentsb of 'voice frequency coming in eine prenssigned sequence. g y

2. In e ieiephone signalling system, e irensinission hue, rneens for impreseino @thereon e Tpiurelliey or signe! currenis or cierent frequencies in the voice renee,` end of e prenseigneol sequence end rnegnitnde seieciiyeiy opereiecisignei receiving eppereius nssocie'vted with seid line nonres onsive ifo voice currens end responsive io in e siggnei currencs ci yoice regnencies 'ne pre nssigned sequence niegniiue.

3. in e ieieyiiione signeiiing ysysce e vtrnnsrniseion line, ineens :for impressing lfiner-erm' e niureiiry oi? sil 'nei currenis ci difeneni `freouieneies in in e Voice in e preessigned sequence, seiec'ciyeiy oper ered signei receiving e-pperetus sssocieiecl Win seid iine9 seni signei eppereius ing nonresponsive io voice currencs end responsive io the sign'ni currenw or ycioe 'ireeuency coming in che nreessigned sequence, et lease one of which rrequeucies is e, coniperelbiyeiy rore componeni oni eine voice current.

e. in combination, o, sequence of irequency seieccing devices und e circuit controlled thereby and normally open at the point of control corresponding y.to the last device and normally closed at the others, and means Ato make each device after'the first operation only in immediate succession to operation of the preceding device, whereby the said v.circuit will be closed ,only by se- I lquential o eration of said'devices with release of al of them before the last. N

5. In combinatioma sequence of three frequency selecting devices and a circuit controlled thereby and normally open at' the point of control corres onding to thel last device 'and normally c osed at the others,v l

and means to make the second andthird devices each operative only inimmediate succession to the preceding device, whereby the said circuit will be closed only by sequential f operation. of. said three' devices and with .different voice frequencies, means release of lthefrst andsecond.

6. In combination, a signaling system comprising a telephone channel and a sig-A naling channel overlapping eachother in frequency and` means responsive only to currents of 'preassigned frequencies and sel quence for renderingvthe signalingcliannel the telephone nonresponsive to currents .of channel. 1 'a p 7.( In aV telephone" voice frequency, a pluralityofgenerators of pressing these on the line in a predetermined sequence, receiving means for said signals having a relay receptive' to the first freuency ltransmit-ted and a 'relay sensitive to t e lastL frequency transmitted and a 'circuit associated with said relays to control a third relay, said circuit having series 4contacts whereby said third -relay is actiatedl only` after the receipt of impulsesv of predetermined frequencies and sequence.

8. The. method of preventing interferencel v due to'voice currents in'k a signaling channel a plurali 'overlapping in frequency the voice level, which consists in rendering the. apparatus of the signaling channel responsive only to signaling. system adapted to transmit ringing currentsv of of currents ofcertain designated frequencies and amplitudes, at least one of which currents is a comparatively rare component of the voice current.

' 9. The method of 'preventing interference due to voice crrentsin a signaling channel overlapping the voice frequency level, which consists in rendering the apparatus of the.

channel responsive only to a plu` si aling ra ity o currents of certain,` designated frev quencies in a designated order of succession, 'each-.current being of a certain minimum amplitude, and the first .thereof rbeing of a frequency which occurs ,in voice currents but occurs rarely with amplitude sufficient to affect the signaling .apparatus 10. In a telephone signal'ingsystem, a line, a signal sending* apparatus comprising a source of a plura ity of currents differing in fr uency, said frequencies being substanltial y'offvoice level, means for associating y saidcurrents with -s'aid line in` predetermined sequence, a signal receiving'ap aratus coniprising a plurality of tuned circuits corresponding in frequency to those of the said source, a relay in each of said circuits, an

energizing circuit for each lof said `relays,a

contact governed bywone'relay v,for closing the ener izing circuit of .another of said relays on y when saidfirst relay .is energized,.

a retaining circuit'for said second relay forl rendering thegsaid contact of the rst relay ineffective to hold said second lrelay de- `energized, a signal relay,. andl means for'v causing an' actuationwof said signal relay when said second relayis'energizedand said y first relay is de`energized.' 1

11. In combination, two

frequency select'- f ing devices and a circuit-controlled therebyl and normally ope n at the point of control, y 'Y corresponding to hsecond device and nor'-,

mally closed -atthep`,oint corresponding to' l 

